With the exception of funerals, I tend to err on the side of underdressing, except for my hat.
I rarely go to funerals, and am not into clothes, end of last year I was pulled up about to enter the water for a swim by the family of a guy I worked with, wanting to be certain I would be at his funeral, quick rush home, find some less than offensive clothing (failed) and run to the church. Jeans, Hawaiian shirt (mostly black) and runners.
T-shirt, jeans and trainers/sneakers are all I own. I think you would want me there not something I'm not.
I could add the hat, now! I am pleased to hear someone address this issue! To much is paid to our apparel! I am not what I wear! But, I would like to feel comfortable in what I choose to wear and everyone else can please themselves as well!